Pipe-punch



I (No Model.)

0, s. OLMSTED.

PIPE PUNCH.

N0.40Z,273,. PatentedApr. so. 1889.

' UNITED STATES PATENT OFFICE.

CLARENCE S. OLMSTED, OF CHICAGO, ILLINOIS.

PIPE-PUNCH.

SPECIFICATION forming part of batters Patent No. 402,273, dated April 30, 1889. Application filed March 5, 1889. Serial No. 301,840. (No model.)

. of Chicago, in the county of Cook and State -of Illinois, have invented certain new and useful Improvements in Pipe-Punches, of which the following is hereby declared to be a full, clear, and exact description, sufficient to enable others skilled in the art to which said invention relates to make and use the same.

The invention relates to punches used for making a series of holes in metal pipe or other tube-like articles.

In Olmsted Letters Patent N 0. 252,241, dated January 10, 1882, there is shown and described a die-carrying mandrel which is inclosed within the metal tube to be punched. The mandrel is divided longitudinally into three parts or sections, the two outer of which conform externally to the curvature of the tube and at their inner flat faces fit the third or central section. This central section has a limited reciprocatin g movement and carries a wedge-like terminal, whereby the outer sections may be spread apart at will to tightly bear against the tube-wall, or on reverse throw of the wedge-section can be released from their grip against the tube. 'One of the outer sections of the mandrel carries the die, and the wedging of such sections against the tube wall just precedes the descent of the punch,

so that a stout firm support is thereby al-f lowed .for the pipe, which, being sustained round about by the expanded mandrel, bears up stiffly to withstand the action of the punch. On reversing the throw of the wedge-section the outer parts of the mandrel relax their grip .upon the tube-wall, so that the tube may be slipped forward a proper distance past the mandrel in position to receive the next descent of the punch and to make the succeeding hole of the series. 7

The present invention is designed to simplify the construction of the sectional mandrel just described; and it consists, also, of certain improvements in the organization of parts for reciprocating the wedge'section of the mandrel, and in a relief device or safetycheck co-operating therewith to prevent break or strain'of the working parts if undue impediment is encountered during the reciprocation of the mandrel-wedge.

The nature of the improvement will fully appear from the description following, and

forming part of this specification, like letters of reference denote like parts of structure throughout.

Figure 1 is a view in longitudinal section of a power-punch embodying the improvements. Fig. 2 is a view of the machine in front elevation; Figs, 8 and 4, perspective views'of the mandrel and of the shifting collar, respectively. Figs. 5 and (3 are detail views in elevation at section-line x 00, Fig. 1, looking toward the front and toward. the back of the machine, respectively. The main bed-frame A of the machine is of substantially rectangular form and affords bearings, as at a, for the drive-shaft B, which derives power, as by gear-wheels b, from main shaft C, having the drive-pulley c thereon.

Upon one end of the bed-frame A is mounted the anvil D, having semicircular seat in its upper face to receive and sustain the tube to be punched. Moving in suitable guideways at the sides of the anvil D is the upright punch-frame E, the punch 6 being secured therein and traveling back and forth with the frame, as well understood. The pitman F, pivoted, as at Z, to the punch-frame and to the wrist-pin f upon the drive-shaft B, actuates the frame in the usual manner. Brackets h, bolted at front and back to the machinebed, have fastened thereto the carrier-rods g,- Which extend the length of the machine in parallel relation, and at the front pass close to the upper edges of the anvil D. The rods 9 carry the saddle i, which slides freely there on, and is furnished with a clip or clamp to shaped to conform to the curvature of the tube. In normal relation the diameter of the mandrel is somewhat less than that of the inclosing-tube, which latter may thus be mounted or removed from position upon the anvil D, or be shifted thereon without difficulty. By moving the mandrel-sections Zm slightly past each other their inclined faces override and thereby expand the diameter of the mandrel sufficiently to cause the same to grip the tube firmly, and so to. sustain the tube against the crushing or indenting tend ency of the punch as it descends to cut the hole. To expand or contract the diameter of the mandrel as desired, one section thereof, as at l, (which carries the die,) is fixedly held by the rod n, forming practically a part thereof, and extending to the back bracket, h, to which it is rigidly fastened. The companion section, m, reciprocates, and is furnished with an oblong slot, 0, to receive and clear away the pipe clippings or chips from the punch. This wedge-section 'm of the mandrel is carried by the bar p, which extends to the back of the machine, and is there pivoted, as at q, to the vibrating stiff lever Q, sustained from the machine-frame. At its lower end the lever Q, (preferably furnished with an anti-friction roll) engages with a cam-collar, s, mounted upon the drive-shaft B, said col lar being secured to the shaft by spline or like joint, so as to have a limited lateral play thereon at the same time that it revolves with the shaft. A reaction-spring, t, set upon the shaft B bears against the collar s, and ordinarily holds the same in proper position to vibrate the lever Q, and consequently to reciprocate the bar 1) a full throw during each revolution of the shaft. The full throw back and forth of the bar 1) and of the wedge-section m of the mandrel carried thereby alternately expands and contracts the mandrel in keeping with the alternating movements of the punch to and from the tube. If, however, a fin, lump, or like ohstruction exists in the tube, so that it is not of smooth even bore, the easy expansion of the'mandrel to grip the tube is prevented. Not only is the wedging action of the mandrel-section m resisted, but a severe and undue strain is developed thereby upon the working parts, which ordinarily is transferred to the lever Q and tends to break such lever or otherwise to spring it out of place.

ing the cam-collar s to the shaft B with a spline or like sliding joint, as detailed, this By securf danger of breakage or disarrangement is entirely prevented. Ordinarily the reactionspring 25 holds the cam-collar s in place to accomplish the full throw of the lever Q, bar p, and mandrelsection m; but when this latter meets with an unusual obstruction to resist its expanding movement then the strain which eventually comes upon leverQ from the revolving cam-collar s is reflected again and causes the collar to ride along the shaft B in opposition to the reaction-spring t,whereby the strain is wholly relieved and the risk of breaking the parts avoided. Manifestly the spring t returns the collar 3 into normal position for full throw as soon as the obstruction in the pipe is removed. The tension of the springt may be adjusted, as shown, for proper action, and it is clear that such spring reacts or compensates in exact keeping with the strain or resistance encountered by the expanding mandrel. The operation of the reciprocating parts is thus rendered true, smooth, and even.

It will be understood that the construction hereinbefore described may be varied within the skill of the mechanic to effect without departing from the spirit of the invention,which latter accordingly is not limited to the precise details.

Having thus described the invention, whatI claim as new, and desire to secure by Letters Patent, is

1. In pipe-punches, the combination, with the reciprocating bar carrying the wedge-section of the mandrel, of the stiff vibrating lever to actuate said bar and the revolving shaft having a cam-collar to engage said lever, sub stantially as described.

2. In pipe-punches, the combination, with the reciprocating bar carrying the wedge-section of the mandrel, of the vibrating lever to actuate said bar, the revolving shaft having cam-collar sliding thereon to engage said lever, and the reaction-spring set upon said shaft and bearing against said collar to control the shift thereof, substantially as described.

3. In pipe-punches, the two-part mandrel divided at an incline longitudinally to form wedge-like contacting sections, one of said sections carrying the die and the other being slot-ted to receive the clippings, and both sections conforming externally to the curvature of the pipe, substantially as described.

CLARENCE S. OLMSTED.

Witnesses:

JAMES H. PEIRCE, II. M. MUNDAY. 

